The invention is directed to a grate plate for thrust grating coolers for cooling hot material, comprising outwardly open troughs arranged at the upper side of the grate plate, whereby a plurality of grate plates having cooling air flowing through them are secured to grate plate carriers that are alternately stationary and reciprocally movable in a grate conveying direction.
In a thrust grating cooler, the grate system is composed of a plurality of stationary and movable grate plate carriers on which are arranged a plurality of grate plates that are provided with openings for cooling air and are essentially flowed-through by cooling air from bottom to top. As viewed in the conveying direction, the stationary grate plate rows alternate with reciprocally movable grate plate rows. The movable rows are secured in common to one or more driven thrust frames seated longitudinally movable, being secured thereto via their correspondingly reciprocally movable grate plate carriers. As a result of the common, oscillating movement of all movable grate plate rows, the material to be cooled, for example the hot cement clinker emerging from a rotary tubular kiln, is conveyed thrustwise and thereby cooled.
A cooler grate plate is known (German Published Application 38 12 425) whose upper side comprises troughs that serve the purpose of accepting and retaining cool material, this material shielding the grate plate from the hot material situated therabove. Such an arrnagement preserves the grate plate and lengthens its useful life. In the known grate plate provided with troughs, U-shaped trough webs are welded into the grate plate members, whereby the inside of the upwardly open troughs is supplied with cooling air from the side through air exit slots that are arranged well above the bottom plate of the grate plates. The cool material received inside the troughs, however, is not prevented from dropping through the lateral air exit slots toward the outside onto the bottom plate of the known grate plate design. This dropped cool material lead to blockages of the air conduits and, thus, to a reduction of the throughput of cooling air through the grate system.
The lateral air exit slots into the troughs of the known grate plate are produced by partial coverings of the upwardly open U-profiles as a result whereof a jamming of the cool material in the troughs can occur. Cool material jammed in the troughs can then impede the oscillating motion of the movable grate plate rows. In the known trough grate plate, moreover, the front plate face, as seen in thrust direction of the grate, and which is especially stressed, is not adequately cooled, as a result whereof the risk of thermal overloading of the grate plate in this region is established.